Adherent articles, such as bandages or adhesive tapes, are commonly used to cover wounds, cuts, blisters, and the like. Such adherent articles typically include an adhesive material that is applied to a substrate material. To use an adherent article, a user can first position a portion of the substrate material over the relevant wound. Thereafter, the user adheres the substrate material to the surrounding areas of skin using the adhesive applied thereto. The adherence of the substrate material to the skin allows the adherent article to be tightly fitted over the wound to protect the wound from infection.
However, one problem associated with conventional adherent articles relates to the removal of such articles from the skin. In particular, a user must typically forcibly tear the article away from the skin to break the adhesive bond of the substrate to the skin. Such tearing often imparts substantial pain to the user. As such, a need currently exists for an adherent article that can be more easily removed than conventional articles.
In response to the discussed difficulties and problems encountered in the prior art, a new adherent article has been discovered. In general, an adherent article, such as a bandage or adhesive tape, of the present invention contains water soluble fibers that allow the adherent article to be removed from human skin with an aqueous solution. In one embodiment, an article of the present invention includes a nonwoven substrate made from water soluble polyvinyl alcohol fibers and a generally water insoluble, dispersible pressure-sensitive adhesive.
In accordance with the present invention, any fibers known in the art to substantially dissolve in aqueous solutions at a certain temperature can generally be used as the water soluble fibers of the nonwoven substrate. For example, fibers that can substantially dissolve in an aqueous solution at temperatures below about 37xc2x0 C., i.e., cold water soluble fibers, can generally be used in a nonwoven substrate of the present invention. In one embodiment, polyvinyl alcohol fibers that can dissolve in water at temperatures between about 20xc2x0 C. to about 35xc2x0 C., or greater, are employed. Moreover, fibers that can only substantially dissolve in an aqueous solution at temperatures greater than 37xc2x0 C., i.e., hot water soluble fibers, can also be used. For example, in some embodiments, polyvinyl alcohol fibers that only dissolve at temperatures of at least 37xc2x0 C. to about 50xc2x0 C. can be used in the present invention.
In addition to water soluble fibers, the nonwoven substrate can also include various other components. In particular, any material that does not affect the solubility of the water soluble fibers can be added. In particular, the nonwoven substrate can include fibers that are generally insoluble and dispersible in an aqueous environment. For example, in one embodiment, the nonwoven substrate can include staple fibers, such as rayon fibers. Moreover, in another embodiment, the dispersible fibers can be pulp fibers either alone or in combination with other fibers. By containing pulp fibers, for example, the nonwoven substrate can be disposed of by applying substantial amounts of water thereto. Conventional water sources, such as faucets or shower heads, can be used to dispense water onto the substrate. After applying water to the substrate, the water soluble fibers substantially dissolve into solution and the remaining pulp fibers disperse such that they can be disposed of by conventional water disposal techniques.
In general, a nonwoven substrate of the present invention typically contains at least 50% by weight of water soluble fibers. In particular embodiments, the nonwoven substrate may contain at least about 70% by weight of water soluble fibers, or least about 80% by weight of water soluble fibers. Moreover, regardless of the amount of water soluble fibers present within the substrate, it is also typically desired that the amount of additional components, e.g., pulp fibers, rayon fibers, etc., applied to the nonwoven substrate not exceed about 50% by weight of the substrate.
In accordance with the present invention, the adherent article also contains an adhesive, such as a pressure-sensitive adhesive applied to the nonwoven substrate to allow adherence of the substrate to a person""s skin. In general, any adhesive that is commonly used to adhere a substrate to human skin can be used in the present invention. In particular, an adhesive of the present invention is typically biocompatible. Moreover, in some embodiments, the adhesive is also water soluble or dispersible such that its adherent properties substantially diminish when contacted with water. For example, one preferred dispersible pressure-sensitive adhesive is HL-9415-X from H.B. Fuller Company
The adhesive can generally be applied in any of a variety of amounts to the nonwoven substrate. For example, in some embodiments, the adhesive can be applied in an amount between about 3 to about 50 grams per square meter, and particularly between about 5 grams per square meter to about 25 grams per square meter.
In addition to the above-mentioned components, an adherent article of the present invention can also contain a variety of components. For instance, the adherent article can also contain an absorbent pad to aid in absorbing medicines, blood, or other fluids from a cut or wound. The absorbent pad can generally be made from any type of material. In particular, in some embodiments, the absorbent pad is dispersible in water to facilitate disposal of the article. One example of a suitable dispersible absorbent pad includes a water-dispersible coform composite material.
Moreover, the adherent article can also include a release liner that is positioned over a portion of the nonwoven substrate to cover and protect at least a portion of the pressure-sensitive adhesive. To use the adherent article, a user can simply peel away the liner from the adhesive-coated substrate and apply the substrate to the skin. In general, the release liner can be made from any commonly used material that can be peeled away from an adhesive, such as plastic films, etc.
Other features and aspects of the present invention are discussed in greater detail below.